The formula you're looking for is technically "average of completed requests per day per team member", so you can take your existing formula as-is, and divide by a distinct count of team member names...

Hello everyone, I have the following problem, I want to compare the same time period for last year, if I have from 03/01/2018 to 03/21/2018, I need to compare in that period but for the 2017 but add...